1. Field of the Invention
The present invention relates to a positioning target for a laminated printed circuit board, and more particularly to a positioning target used in a printed circuit board having at least two pressing.processes in manufacturing the printed circuit board.
2. Description of Related Art
A printed circuit board is composed of at least two base layers pressed together. When these at least two base layers are pressed, because there is glue applied among a nucleation surface of each of the at least two base layers, the at least two base layers might easily slip away from the proper pressing location, which leads a mis-alignment among the at least two base layers. Furthermore, because each of the at least two base layers has metal wires printed thereon, when mis-alignment occurs among the at least two base layers, there will be no electrical conduction between wires of the at least two adjacent base layers. Therefore, it is important to have perfect alignment among base layers in the pressing process while making the printed circuit board.
With reference to FIG. 4, a conventional positioning target board (60) for a laminated printed circuit board having at least two pressing processes has multiple positioning points, i.e., P1, P2, P3, P4, P5, P6, P7, P8, P9, P10. The positioning target board (60) is used to position the base layers when in a process of manufacturing a laminated printed circuit board. The positioning points P1, P2, P3, P4, P5, P6, P7, P8, P9, P10 listed on the positioning target board (60) are for illustrative purposes only and not limited to the manner shown.
The positioning target board (60) is used to position two base layers when pressed together. That is, when two base layers are to be pressed together, the two base layers are first applied with glue on a nucleation surface of each of the base layers. After the glue is applied, the two base layers are aligned with the positioning target board (60) and positioning means such as rivets, pins or the like are used to extend through P1, P2, P4 and P5 respectively (and possibly also P3 and P8) and the two base layers so as to correctly align and position the two base layers. The reason P3 and P8 are not necessarily required to have a positioning means is that the purpose of having P3 is to ensure that the positioning target board (60) has only one orientation to match a tool used to press the two base layers together. After the two base layers are perfectly pressed together, a part of the glue applied on the nucleation surfaces of each of the base layers will be forced to flow out of edges of the combined base layers. To remove the edges with glues from the combined base layers, the user will have to cut off edges containing the P1 and P2, and P4 and P5. When another base layer is to be pressed together with the combined base layers, positioning means is again used to extend through P6, P7 and P9, P10 and the base layers so as to position all the base layers. Then, the tool is applied to press the base layers together, which also results in the outflow of the glue applied on nucleation surfaces between two adjacent base layers. Again, the user will have to cut off edges containing P6, P7, P9 and P10 to complete the manufacture of the laminated printed circuit board. In order to have the laminated printed circuit board have a clear cut, the distance between every cut should be at least one inch (2.54 cm). That is, a distance required in the edges of the positioning target board (60) during the entire process in manufacturing the laminated printed circuit board depends on a cut quantity. For example, when the cut quantity increases, e.g., four, five or even six times are required, the distance on the edges of the positioning target board (60) and to be cut in the manufacturing process increases.
The vertical arrangement of the positioning points P1, P2, P3, P4, P5, P6, P7, P8, P9, P10 with respect to each end side of the positioning target board (60) leads to a waste in material of the positioning target board (60) and thus a reusing rate for the positioning target board (60) is therefore reduced.
To overcome the shortcomings, the present invention tends to provide an improved positioning target board structure to mitigate and obviate the aforementioned problems.
The primary objective of the present invention is to provide a positioning target board for manufacturing the printed circuit board, wherein the positioning target board has multiple positioning points each defined along a length of each end side of the positioning target board. With this arrangement, the user only needs to cut a small portion on the end edge with an overflow of the glue. Therefore, material and cost are saved.